S340 I. J. Radiation Oncology d Biology d Physics Volume 75, Number 3, Supplement, 2009

(50-175 mg) and Versed (3-12 mg). Local anesthetic was given with a mixture of 1% Lidocaine, 0.25% Marcaine, 1:100,000 Epi-nephrine, and 4% Sodium Bicarbonate neutralizing solution (20-120 cc). Local anesthesia was given to a 5 x 5 cm perineal area toa depth of 10 cm under TRUS guidance. The implants were placed under mobile multi-plane prostate template (Radiation TherapyProducts Prostate Template) guidance using from 3 to 4 planes, and 12 to 22 needles. Needle spacing was 1.0 cm. The implantprocedure included sigmoidoscopy and cystoscopy.

Results: Between 2002 and 2009, 467 TRUS guided prostate implants were performed under local anesthesia. Median implanttime was 45 minutes (range : 30 to 150 minutes). HDR treatment was given using the Nucletron afterloading system. The implantvolume received 2,250 cGy in 3 fractions prescribed to the 100% Isodose line, given over 24 hours. Urethral dose points (12-16)were followed, and limited to # 105% of the prescription dose. The procedure was well tolerated, with all patients having com-pleted the procedure. Three patients developed respiratory suppression, and required reversal with Narcan. All recovered unevent-fully. Otherwise, there have been no acute complications to date.

Conclusions: TRUS interstitial implant of the prostate under local anesthesia is feasible. Implant time, complications, cost, andscheduling convenience, compare favorably to general or spinal anesthetic technique.

Author Disclosure: J. Lara, None; R.J. Mark, None; P.J. Anderson, None; R.S. Akins, None; M. Nair, None.

2353 Preliminary Results in Prostate Cancer Patients Treated with High Dose Rate Brachytherapy and Intensity

Modulated Radiation Therapy (IMRT) vs. IMRT Alone

R. B. Wilder, G. A. Barme, R. F. Gilbert, R. E. Holevas, L. I. Kobashi, R. R. Reed, R. S. Solomon, N. L. Walter, L. Chittenden,K. M. Tokita

Cancer Center of Irvine, Irvine, CA

Purpose/Objective(s): To analyze preliminary results with high dose rate (HDR) brachytherapy and intensity modulated radiationtherapy (IMRT) vs IMRT alone for prostate cancer.

Materials/Methods: Between October 2003 and August 2008, 281 patients with early-stage prostate cancer underwent HDR bra-chytherapy to 2,200 cGy in 4 fractions bid and IMRT to 5,040 cGy (n = 239) in 28 fractions or IMRT alone to 7,920-8,100 cGy in44-45 fractions (n = 42).

Results: Median follow up was 1.9 years. Patients treated with HDR brachytherapy and IMRT had a lower National Comprehen-sive Cancer Network (NCCN) recurrence risk (p = 0.05) and a lower likelihood of having diabetes mellitus (p = 0.04) than patientstreated with IMRT alone. There was no significant difference in terms of the percentage of patients receiving hormonal therapy byradiotherapy treatment group (p = 0.77). There have been 2 recurrences in intermediate-risk patients and 2 recurrences in high-riskpatients. The 2-year biochemical disease-free survival (bDFS) rates using the Phoenix consensus definition in low-risk, interme-diate-risk, and high-risk patients treated with HDR brachytherapy and IMRT are 100%, 98% (95% confidence interval (CI) 94-100%), and 97% (95% CI 92-100%), respectively. The 2-year bDFS rates in low-risk, intermediate-risk, and high-risk patientstreated with IMRT alone are 100%, 100%, and 67% (95% CI 13-100%), respectively. There was no significant difference inbDFS between treatment groups when groups were stratified by NCCN recurrence risk (p = 0.71). Similarly, there was no signif-icant difference in bDFS between treatment groups when only the high-risk subgroup of patients was examined (p = 0.28). In low-risk patients, the presence of bilateral positive core biopsies did not affect bDFS (p = 1.00). The 2-year rates of at least NationalCancer Institute Common Terminology Criteria for Adverse Events v3.0 grade 2 gastrointestinal toxicity for HDR brachytherapyand IMRT vs IMRT alone were 14% (95% confidence interval (CI) 8-20%) vs 7% (95% CI 0-16%), respectively (p = 0.32). The 2-year rates of at least grade 2 genitourinary toxicity for HDR brachytherapy and IMRT vs IMRT alone were 16% (95% CI 9-23%) vs5% (95% CI 0-14%), respectively (p = 0.30). At 2 years post-irradiation, erectile function had worsened in 12% (95% CI 7-17%) vs9% (95% CI 0-21%) of men treated with HDR brachytherapy and IMRT vs IMRT alone, respectively (p = 0.34). There was nosignificant difference in acute toxicity (p = 0.09) or late toxicity (p = 0.32) by treatment group.

Conclusions: HDR brachytherapy and IMRT yielded similar short-term bDFS and toxicity to IMRT alone. As a result, wecontinue to base treatment on physician and patient preference.

Author Disclosure: R.B. Wilder, None; G.A. Barme, None; R.F. Gilbert, None; R.E. Holevas, None; L.I. Kobashi, None; R.R.Reed, None; R.S. Solomon, None; N.L. Walter, None; L. Chittenden, None; K.M. Tokita, None.

2354 Analysis of Impact of Hormonal Therapy on Prostate Cancer Patients Receiving High-dose IMRT: Long

Term Follow-up

S. Vora, W. W. Wong, K. Wharton, G. A. Ezzell, S. E. Schild

Mayo Clinic Arizona, Scottsdale, AZ

Purpose/Objective(s): The impact of androgen deprivation therapy (ADT) on patients receiving high dose IMRT is not well un-derstood. Randomized trials comparing external beam irradiation (EBRT) plus ADT with EBRT alone suggested survival benefitsfor the combined modality treatment for (pts) with intermediate or high risk diseases. However, these studies used EBRT dose ofabout 70Gy. This retrospective review evaluated the impact of ADT in 288 patients who received either high-dose IMRT or high-dose IMRT in combination with hormonal therapy.

Materials/Methods: A retrospective review of all patients with localized prostate adenocarcinoma treated with high-dose IMRTwas conducted. Eligible patients had a minimum of two years of follow-up Patients received 5 or 7 field IMRT delivering 75.6 or77.4 Gy to the prostate and 50.4 Gy to the seminal vesicles. Transabdominal ultrasound was used to reduce risk for geographicmiss. ADT consisted of leuprolide only. Biochemical control rates were calculated according to the ASTRO-Phoenix consensusdefinition. Risk groups were designated on the basis of presence or absence of pretreatment PSA level 10 ng/ml or less, stage T1-2and Gleason Score # 6. Median follow-up was 62 months (range 3.9 - 98.9 mo).

Results: Of 288 pts, 102 received hormonal therapy as part of treatment (31 neoadjuvant+concurrent, 52 neoadjuvant+concurren-t+adjuvant, 5 concurrent+adjuvant, 14 adjuvant only). Median duration of ADT was 12 months. The 3 and 5 yr biochemical controlrates (BCRs) were 91.8% and 85.2% (with any ADT) and 95.5% and 87.4% (without ADT) (p = 0.71). The 5-year BCRs by riskgroups were low risk: 85.7%(n = 9) with ADT, 93.4%(n = 90) without ADT (p = 0.87); intermediate risk: 93%(n = 55) with ADT,

Proceedings of the 51st Annual ASTRO Meeting S341

84.1%(n = 81) without ADT (p = 0.25); high risk: 75.1%(n = 36) with ADT, 73.4%(n = 14) without ADT (p = 0.86). Univariateanalysis also failed to yield a statistical difference in BCR based on timing of hormonal therapy. In patients receiving ADT, therewas no improvement in patients based on duration of hormonal therapy(.12 months vs.\12 months)(p = 0.18). Univariate anal-ysis demonstrated that the administration of hormonal therapy (p = 0.0009) and higher risk groups (p\0.0001) were associatedwith poorer survival. Multivariate analysis using the Cox proportional hazards revealed that risk groups was significantly(p = 0.0062) associate with survival but that hormonal therapy (p = 0.07) was not.

Conclusions: This analysis of 288 patients who received high-dose IMRT failed to see any statistical significance with the additionof ADT in terms of biochemical control and overall survival. Randomized studies are needed to evaluate the benefits of addingADT to EBRT compared to EBRT alone when higher radiation doses are being used.

Author Disclosure: S. Vora, None; W.W. Wong, None; K. Wharton, None; G.A. Ezzell, None; S.E. Schild, None.

2355 Excellent Biochemical Control and Late Toxicity after Moderately Hypofractionated Adjuvant Helical

Tomotherapy: Updated Results of a Phase I-II Study

G. Berardi1, C. Cozzarini1, C. Fiorino1, F. Alongi1,2, A. Chiara1, P. Mangili1, L. Perna1, R. Valdagni3, P. Rigatti1, N. G. Di Muzio1

1Scientific Institute San Raffaele, Milan, Italy, 2IBFM-National Research Council (CNR), Cefalu (Palermo), Italy, 3ProstateProgram, Fondazione IRCCS-Istituto Nazionale dei Tumori, Milan, Italy

Purpose/Objective(s): To report the updated results on late toxicity (tox) findings and clinical outcome of a moderately hypofrac-tionated adjuvant (ADV) RT with Helical Tomotherapy (HFHTT) after pelvic lymphadenectomy and radical retropubic prostatec-tomy (PL+RRP) for node-negative carcinoma of the prostate (CaP).

Materials/Methods: From 1/2005 to 3/2006, 50 consecutive patients submitted to PL+RRP for a node-negative, high-risk, CaPwere enrolled in a Phase I-II trial to receive 58 Gy/20 fractions (5/week) on prostatic bed (PB). The estimated corresponding valuesof 2 Gy equivalent dose (EQD2) were comprised between 62 Gy (a/b = 10) and 73 Gy (a/b = 1.5). Endpoint was to verify a risk oftoxicity and biochemical failure not exceeding that observed in our high-doses (68-72 Gy at 1.8 Gy/fraction, median 70.2 Gy),conventionally fractionated 3DCRT (CFRT) series. For this purpose, the outcome of HFHTT cohort, mainly composed ofpT2R1 (n = 15) and pT3a (n = 32, positive surgical margins in 11) was compared to that of 175 comparable (45 pT2 R1 + 130pT3a, R0/R1 58/72) cases treated with ADV CFRT. Patients characteristic (iPSA=initial PSA, GS=Gleason score, AHT=ADVhormonotherapy; mFU=median follow-up): HFHTT: iPSA 7 ng/mL; GS (%) #6/7/$8 : 10/68/22; AHT in 14% (median 20mos); mFU 45 mos. CFRT : iPSA 9 ng/mL; GS (%) 42/40/18; AHT in 18% (median 12 mos); mFU 73 mos.

Results: Thus far, only 1 pts in the HFHTT group exhibited a PSA failure at 35 mos, with a PSA kinetics highly suggestive forsystemic failure, as compared to 28 (16 # 45 mos) in the CFRT cohort. Frozing the FU at 45 mos (the mFU of HFHTT group) the45-mos biochemical relapse-free survival (bRFS) was 98% vs 88% (p = 0.05) in HFHTT and CFRT groups, respectively. LateGastro-intestinal (GI) tox of HFHTT was excellent with only 1 pts experiencing late Grade 2 proctitis without any other Grade. 1 GI tox, as compared to 9 (5%) Grade $ 2 (one Grade 3) observed in the CFRT cohort. Nevertheless, late Genitourinary(GU) tox of HFHTT was slightly higher than that of CFRT, with 13 (26%) late Grade $ 2 events as compared to 20%(p = 0.36), and 10% vs 6.5% (p = 0.41) Grade $ 3 (of which one Grade 4 in both groups, p = 0.30), respectively. Of note, 5/5pts experiencing late Grade $ 3 GU tox in HFHTT cohort were hypertensive, as compared to 6/11 in CFRT group.

Conclusions: the promising 45-mos bRFS of pts treated with HFHTT is strongly suggestive of an a/b ratio for residual CaP after RRPbelow 3, and is consistent with a radiobiologic model postulating a 3% gain of 5-year bRFS for every additional EQD2 Gy delivered inthe postoperatiive setting. The increased GU toxicity recorded mainly in pts with hypertension may suggest extreme caution in ex-ploring hypofractionated regimen in hypertensive patients. A phase III study comparing HFHTT to CFRT is highly suitable.

Author Disclosure: G. Berardi, None; C. Cozzarini, None; C. Fiorino, None; F. Alongi, None; A. Chiara, None; P. Mangili, None;L. Perna, None; R. Valdagni, None; P. Rigatti, None; N.G. Di Muzio, None.

2356 Adoption of Evolving Intra-operative Treatment Planning Software Has Resulted in Improved Post-

operative Prostate Seed Implant Dosimetry

D. L. Simmons, J. A. Cesaretti, R. D. Nurani, R. D. Hixson, J. Paryani, R. Jhamnani, M. D. Terk

Florida Radiation Oncology Group, Jacksonville, FL

Purpose/Objective(s): Within the context of a high volume prostate seed implant program, we reviewed our experience with 475consecutive patients treated with the four most recent versions of the Variseed TM (Varian Inc, Palo Alto, CA) intra-operative treat-ment planning software in order to evaluate the impact of these technological improvements on patient care.

Materials/Methods: From May 2000 to December 2008, 475 patients were treated with I-125 monotherapy with a prescriptiondose of 160 Gy. All patients had both intra-operative and 1 month post-operative dosimetric parameters available for analysis. Im-plants were performed using a peripheral loading strategy with real-time ultrasound guided seed placement. Intraoperative dosim-etry with the various Variseed systems were used to optimize prostate coverage and minimize rectal and urethral doses. Variseedversions 6.7, 7.0, 7.1 and 7.2 were utilized as soon as they became commercially available. Seed implants were performed at 6facilities by 8 different physicians. Differences in proportions were tested using the chi-square test.

Results: Intraoperative PD90\160 Gy occurred in 8% of patient’s treated with Variseed version 6.7, and #1% of patients withsubsequent software versions (p \ 0.04). Post-operative PD90\160Gy improved from Variseed 7.0 to 7.2 from 19% to 7%(p\0.05). Post-operative PD90\140Gy was very rare in all software versions, occurring in \1% of all patients. The incidenceof intra-operative PV100\95% progressively improved to 39%, 16%, 10% and 3% for Variseed versions 6.7, 7.0, 7.1, and 7.2respectively (p\0.04). The incidence of a post-operative PV100\95% progressively improved to 57%, 67%, 44% and 31% forversions 6.7, 7.0, 7.1 and 7.2 respectively (p\0.04). Intra-operative and post-operative dosimetric quality parameters for rectaltoxicity have been unchanged throughout the application of the new software versions, with of \5% of all patients receivinga post-operative RV100.1.0 cc. The incidence of intra-operative UD30.240 Gy has been consistent at 0%-3%. However, thepost-operative UD30 . 240 Gy steadily decreased from 31% to 3% with subsequent versions of Variseed (p\0.01).